The invention relates to a portable, easily composable supporting skeleton which serves preferably as a supporting structure of buildings composable in situ and their components, especially roof tosses of provisionally erected buildings, tents, sports facilities, exhibition grounds, scenographies and even bridges and/or similar structures.
According to the International Patent Classification (IPC.sup.6) the inventions of this kind are classified into the field of three dimensional framework structures (E 04 B 1/19) or into the field of construction elements consisting of bar-shaped building elements (E 04 B 1/58) or also in the field of connections between individual parts of skeletons used in construction (E 04 G 7/00).
The invention is based on the problem how to conceive the simplest possible skeleton of interconnected bar-shaped elements, in which as many skeleton components as possible remain interconnected also when in a partly disassembled state, foreseen, for example, for transport or storage, which will result in the smallest possible volume required by the skeleton when transported or stored; on the other hand the skeleton should be quickly and easily composable in situ, without any special accessories and in the shortest possible time.
In the DE 38 00 547 A1 the so called set of building elements for framework structures is described, which consists essentially of cylindrical node elements with longitudinal running grooves arranged uniformly over their circumference. The grooves are intended for the insertion of preferably pipe-like supporting rods with adequately reinforced ends. Such a set represents no doubt a relatively simply composable supporting structure which can be erected stepwise into a rod assembly or a suitable skeleton, and then also disassembled, always in situ. From an overall viewpoint the individual component parts require during transport and storage relatively small room with respect to the dimensions of the entire skeleton. However, this type of structure is deficient, among other reasons also because of the possibility that individual component parts easily get lost or are mislaid during the disassemblage and assemblage, which often causes delays in fulfilling obligations, or leads even to improvisations, which, as a rule, mean a substantial reduction of the bearing capacity of the entire skeleton. Besides, it shall be added, that the stepwise assemblage of a skeleton is a time-consuming job. Each individual rod shall be screwed one by one into the adequate joint elements. Besides, the screwing has to be performed in different positions, at different angles and even in high positions. It often happens, that the rods with the male thread are damaged during transportation, the threads are namely smashed, which can essentially render difficult and extend the assemblage of the structure. Similarly, e.g. due to dirt, especially in assembling in the field, e.g. in situ, some of female threads in the node element can be damaged, too. This kind of inconvenience is extremely difficult to eliminate, for cleaning of inner threads is a complicated procedure; therefore, it often occurs in practice, that rods are screwed forcibly in inadequately cleaned openings. Such procedures almost surely lead to the destruction of at least one thread in the node element, which means in general, that the node element as a universal unit is no longer usable.
A similarly conceived solution is known also from PCT/HU90/00015, in which the node element shaped like an octahedron, icosahedron or similar multiangular solid is enclosed with a sort of envelope by means of which the screw heads are tightened to the node element; then it is possible to screw the rods with thread openings at their ends on the screw stems. The problems arisings with this invention are very similar to those occuring with the invention according to the before mentioned solution described in the DE 38 00 547 A1.